Fix migrations

apps/map/migrations/0060_project_life_span_null.py

@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.6 on 2018-05-24 22:19
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+
+def null_life_span(apps, schema_editor):
+    CaseStudy = apps.get_model('map', 'CaseStudy')
+    CaseStudy.objects.filter(project_life_span=None).update(
+        project_life_span=''
+    )
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('map', '0059_auto_20180519_1801'),
+    ]
+
+    operations = [
+        migrations.RunPython(null_life_span),
+    ]

apps/map/migrations/0061_auto_20180523_1659.py

@@ -8,7 +8,7 @@ from django.db import migrations, models
 class Migration(migrations.Migration):
 
     dependencies = [
-        ('map', '0059_auto_20180519_1801'),
+        ('map', '0060_project_life_span_null'),
     ]
 
     operations = [